Concrete stack



W. M. ALSTON.

CONCRETE STACK.

APPLICATION FILED JAN. 9, 1919.

1,344,608. Patented J 11116 29, 1920.

I ENTOR I outer shell UNITED STATES PATENT OFFICE.

DUNIBAR-ALLEN COMPANY,

ASSIGNOR TO THE BAKER- CORPORATION OF OHIO.

CONCRETE STACK.

Application filed January 9, 1919. Serial No.

To all whom it may concern:

Be it known that I, WALTER M. ALsToN, a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Concrete Stacks, of which the following is a specification.

This invention relates to chimneys or stacks and particularly to large chimneys and stacks such as used at power plants and with furnaces of various kinds.

The object of the invention is to provide a chimney or stack having an external permanent shell and an internal lining supported from said external shell in a manner to permit of its ready renewal, the whole structure forming a stack or chimney which is strong, economical to erect and easy to repair.

In the accompanying drawing, Figure 1 is a sectional elevation of a stack embody ing the invention; Figs. 2 and 3 are vertical sectional views of portions of the stack on an enlarged scale to more clearly show the construction; Fig. 4c is a horizontal section on an enlarged scale taken on the line 44, Fig. 1; Fig. 5 is a plan view and F ig. 6 an outside elevation showing the means for supporting the lining.

The improved stack comprises the outer shell, or stack proper 1, and the internal lining 2 supported from the outer shell, and with an air space 3 between the same.

The stack proper is constructed of concrete or other cementitious material, and preferably has embedded therein suitable metal reinforcements, shown as consisting of vertical rods 4 and horizontal bands 5, but obviously various forms of metal reinforcement will answer the purpose. This is preferably formed of the cementitious mixture known as gunite which as known is a mixture of cement and sand with water, and is applied by means of a so-called gun which, by means of compressed air or the like, forcibly sprays the cementitious mixture in place, the force used being sufiicient to eliminate the moisture almost instantly, as a consequence of which the mixture sets very rapidly. To construct this outer shell a suitable internal form will be provided, with the reinforcement placed around same, and the "gunite is then applied by means of the gun, be-

Specification of Letters Patent.

V the annular supports formed Patented June 29, 1920.

ginning at the bottom and working upwardly,the gunite being applied until a wall or shell of the desired thickness is formed; and as the composition sets very rapidly the structure becomes self-supporting as it is built up. The reinforcement will be erected in sections, and the internal form will be raised from section to section as it is being constructed,the section under construction being supported entirely by the sections below.

Before applying the gunite, suitable internal brackets are secured to the rein forcement and become embedded in the ce ment when it is applied. These brackets are indicated by the reference numeral 7, and they project inwardly beyond the inner face of the outer shell, preferably to varying distances,those at the lower portion of the stack projecting inwardly farther than those at the top of the stack so that the internal lining is substantially vertical, while the stack proper is preferably tapered ,as shown. These brackets are provided at their inner ends with horizontal ledges 8 and upwardly and downwardly projecting flanges. 9, and serve to support annular members on which the lining 2 is erected. These annular members are formed by a series of segmental plates 10, provided at their outer edges with upwardly and downwardly projecting flanges 11, and have their ends supported on and secured to the horizontal ledges 8 on the brackets. To allow for expansion and contraction, the securing means is so arranged as to'permit radial movement of the suporti-ng plates 10. This is obtained by securing the plates 10 to the brackets 7 by means of bolts 12 extending through elongated holes in the plates and brackets, the holes in the brackets having their long axes extending radially of the stack and the holes 14: in the plates having their long axes extending circumferentially of the stack. Thisallows a limited movement of the plates.

The internal lining 2 is preferably formed of fire or other brick and is erected in sections, the lowermost section resting upon the foundation while each section thereabove rests upon'and is supported by one of by a series of plates 10. As a consequence, any section of the lining can be torn down and rebuilt Without destroying the'entire lining, so that the lining can be readily and cheaply repaired when necessary.

The reinforced outer shell or stack proper is comparatively thin but nevertheless .exceedingly strong and its method of erection does not require expensive scaffolding and forms, thus making its erection relatively cheap. The internal lining is spaced from the outer shell and consequently can expand or contract independently of the outer shell, and since it is built up in sections, each independently supported, it can be quickly and economically repaired.

The stack can have applied to it any suitable ladder, such as shown at 16. Supports for it will be anchored to the reinforcement before the cement is applied.

I claim:

1-. A stack or chimney comprising an outer unitary self-sustaining shell of cementitious material, inwardly-extending annular brackets supported by said shell at vertical intervals thereof, and an internal lining formed in sections each supported by one of said brackets, whereby said outer shell forms the sole support for itself and for said lining sections.

2. A stack or chimney comprising an outer unitary self-sustaining shell of reinforced cementitious material, inwardly-extending annular brackets having their outer ends embedded in said shell at vertical intervals thereof, and an internal lining formed in sections each supported by one of said brackets, whereby said outer shell forms the sole support for itself and for said lining sections.

3. A stack or chimney comprising an outer shell of cementitious material, a plurality of annular series of brackets embedded therein, supported thereby and extending inwardly therefrom, supporting plates held by said brackets and movable radially thereon, and lining sections erected on said plates.

In testimony whereof, I have hereunto set my hand.

WALTER M. ALSTON. 

